Do you value tails on cresties? Because young geckos in particular are very prone to hunting down tails of tankmates as they have a very tuned hunting instinct.
As well, I could direct you to a couple threads on another forum that show the results of housing two young geckos together. One pair were clutchmates, and "got along just fine". Another pair were from different parents, and again, seem to cohabit without issues. The end result in both cases? Both baby geckos lost limbs - one a foot, the other an entire leg - to an overambitious tankmate.
One of my adult females also used to be housed with another when a different breeder owned her because they were both non-aggressive towards each other. Until one day for no apparent reason, my gecko hunted down and attacked her tankmate, and left her with some pretty bad wounds. Hence the reason the breeder sold her to me in the first place.
So, in short, as Aimless suggested, no, you should not house your gecko with another, especially at this age, and unless and until you gain a lot more experience working with the species. You have to be vigilant in monitoring them, because they can turn on each other at any time, and the results can be severe. Very experienced breeders have even been caught off guard with this type of behavior. For example, one of our local (and very reputable breeders) who has been in the business for years posted pics of her geckos and gecko setups to show how even a pair of females, who got along fine and were provided with a huge enclosure and adequate cover/hides/food bowls, had to be separated because they turned on each other one day, and she caught her one female gripping the other female by the head, and violently shaking her. Had the breeder not interfered immediately, her gecko very well could have died. These things happen.
If you don't want to deal with this risk to your animals, keep them separate. There is no need to house them together.